Winter Weather Update for this weekend
Good Tuesday morning everyone! Please note the time of this update is 6am Tuesday December 4th. I mention this as there will be several updates as we go through the week with information for this weekends potential for winter weather here in the county. The models continue to indicate we will see some winter weather this weekend. The timing of the storm continues to adjust a little. Looking at the arrival on Saturday the afternoon and evening hours. My biggest concern is the ice potential is creeping up more and more with this event. Let's take a look at the current model data. Starting with the GFS.
As we move through the daytime hours on Saturday we will see rain begin to move into the county. This system will begin to transition to a wintry mix as we move into the evening and overnight hours into Sunday morning. This will all be cause primarily by cold air being trapped against the eastern slopes of the mountains. The real question remains of how much cold air. How far out it expands and how dense the cold air is in the atmosphere. This is going to make all the difference in the world between just rain, snow, sleet or freezing rain. If the layer of cold air is shallow we will be looking at more of an ice vent and less of a snow and rain event. The model data does show a transition throughout the afternoon and evening hours of Saturday into Sunday morning. The images below will show what the models are expecting. Once you scroll past the images I will have more detail.
The two images above indicate the chance for all snow by 7pm Saturday evening around the county. That is the blue areas on the map. One word of caution the gradient is really tight on this now so we could be looking at all rain in reality with some sleet or freezing rain mixing in. The second image shows a very tight gradient with snow sleet and freezing rain around the county. Snow is blue, sleet is orange and freezing rain is purple. That gradient is so tight in this model we will likely see all three during the overnight hours into Sunday morning.
By Sunday morning we could see all sleet with the system as the cold air aloft starts to get very shallow into the atmosphere. As the air continues to thin out and warm air starts to move in we will likely transition back to freezing rain and then all rain. by Sunday afternoon.
As you can see from the model data above the GFS is expecting us to see all forms of precipitation with this event from rain, snow, sleet and freezing rain. The question continues to remain for how long of each type and how much. Let's take a look at the accumulation totals by each model. Again remember this will look inflated because the models don't differentiate the different types of accumulation very well.
The GFS is shoving 19 inches of snowfall for the county. This is highly unlikely with the very limited amount of dense cold air from the system. That is why I am leaning toward this being an event with some ice accumulation taking away from this total.
The European Model shows us with the chance of seeing 14 inches of snowfall. Again this total is likely very overstated due to the probability of ice accumulation taking away from these totals.
The ensemble models are indicating we could see 7 inches of snowfall. This again seems to be a little inflated with the ice potential. Now let me just ease your minds here about the ice potential. These totals seem very inflated as ice accumulation is obviously more dense than the other types of accumulation with rain and snow. The ice appears more solid in the data which causes these totals to become very high. We could only see a tenth of an inch of ice from this system. We are certainly not looking at any catastrophic amounts of ice in the event. I just wanted to clarify that so no one became concerns as this was a gloom or doom type of forecast.
As of right now I am still leaning toward 3-5 inches of snowfall around the county with the added chance of some ice accumulation of up to a tenth of an inch. These totals will continue to be adjusted as we move closer to the weekend and the models continue to get a much clearer picture on what we can expect from the system. I will bring out the snow meter for the first time this season and post it on social media today. As always thank you for following Rowan County Weather.